Main feedwater system for improving water supply reliability of high temperature gas-cooled reactor steam generators

Abstract

The present invention discloses a main feedwater system for improving the water supply reliability of a high-temperature gas-cooled reactor steam generator, comprising a main feedwater pump and a high-pressure heater. The main feedwater pump comprises a first main feedwater pump, a second main feedwater pump, and a third main feedwater pump. The first main feedwater pump, the second main feedwater pump, and the third main feedwater pump supply water to two steam generators through a main pipe, and the feedwater flow rate of the steam generators is regulated by a main feedwater flow regulating valve of the steam generator. The present invention regulates the feedwater flow rate of the steam generator through the main feedwater flow regulating valve of the steam generator, and the speed of the main feedwater pump is only used as an auxiliary regulation method, so that no isolation valve and check valve are required between the outlet main pipe of the standby main feedwater pump and the operating main feedwater pump, thereby achieving the simultaneous connection of three main feedwater pumps to the outlet main pipe. When any two main feedwater pumps are in operation, the remaining main feedwater pump is on standby, thereby improving the water supply reliability of the main feedwater system and reducing unplanned reactor shutdowns.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature gas-cooled reactors, and in particular to a main water supply system for improving the water supply reliability of a steam generator of a high-temperature gas-cooled reactor. Background Art

[0002] The primary function of the main feedwater system in a high-temperature gas-cooled reactor nuclear power plant is to provide feedwater at rated pressure and flow to the steam generators, while also providing water heating and feedwater recirculation. Feedwater enters the steam generators, dissipating heat from the primary circuit and is a critical system for ensuring the safe operation of the power plant.

[0003] At present, the high-temperature gas-cooled reactor nuclear power plants under construction in China adopt the "double-reactor with one unit" approach. Figure 1 As shown, the main feedwater system is equipped with three main feedwater pumps: the first, second, and third. The first and second main feedwater pumps each correspond to a steam generator, while the third main feedwater pump serves as a backup, providing backup for either the first or second main feedwater pump. An isolation valve is installed between the third main feedwater pump and the outlet headers of the first and second main feedwater pumps. Because the current design primarily controls the feedwater flow to each steam generator by adjusting the main feedwater pump speed, and because the feedwater flow to both steam generators needs to be controlled separately, the third main feedwater pump can only provide backup for one of the main feedwater pumps. If the unused backup main feedwater pump fails, the corresponding reactor will be shut down. Furthermore, because each high-pressure heater corresponds to one steam generator, a failure of the high-pressure heater would subject the corresponding steam generator to significant temperature shock, hindering steam generator operation. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a main water supply system for improving the water supply reliability of a high-temperature gas-cooled reactor steam generator.

[0006] The present invention proposes a main water supply system for improving the water supply reliability of a high-temperature gas-cooled reactor steam generator, comprising:

[0007] Main feed water pumps, the main feed water pumps comprising a first main feed water pump, a second main feed water pump, and a third main feed water pump, wherein the outlet ends of the first main feed water pump, the second main feed water pump, and the third main feed water pump are simultaneously connected to a main pipe, and the first main feed water pump, the second main feed water pump, and the third main feed water pump supply water to two steam generators through the main pipe, and the feed water flow of the steam generators is adjusted by the main feed water flow regulating valves of the steam generators;

[0008] A high-pressure heater is arranged between the main feed water pump and the steam generator, and is used to heat the feed water. The high-pressure heater includes a first high-pressure heater and a second high-pressure heater, and the outlet pipelines of the first high-pressure heater and the second high-pressure heater are connected.

[0009] In some embodiments, when any two of the first main water supply pump, the second main water supply pump and the third main water supply pump are in operation, the remaining main water supply pump is on standby.

[0010] In some embodiments, the outlet pipelines of the first high-pressure heater and the outlet pipeline of the second high-pressure heater are connected via a connecting pipeline.

[0011] In some embodiments, a first valve is provided on the communication line.

[0012] In some embodiments, the first high-pressure heater and the second high-pressure heater backup each other, and when the first high-pressure heater or the second high-pressure heater fails, the first valve is opened.

[0013] In some embodiments, the steam generator includes a first steam generator and a second steam generator, and the first valve is closed when the first high-pressure heater and the second high-pressure heater provide water to the first steam generator and the second steam generator respectively.

[0014] In some embodiments, inlet ends of the first high-pressure heater and the second high-pressure heater are connected to the main pipe.

[0015] In some embodiments, the feedwater flow rate of the steam generator is assisted in being regulated by adjusting the rotational speed of the main feedwater pump.

[0016] In some embodiments, the main water supply flow regulating valve includes a main regulating valve and a bypass regulating valve, and the main regulating valve and the bypass regulating valve are arranged in parallel.

[0017] In some embodiments, a deaerator is provided upstream of the main feed water pump, and the deaerator is used to remove oxygen from the feed water.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention controls the feed water flow of the steam generator through the main feed water flow regulating valve of the steam generator, and the main feed water pump speed is only used as an auxiliary regulation method, so that there is no need to set an isolation valve and a check valve between the outlet main pipe of the standby main feed water pump and the operating main feed water pump, and realizes that three main feed water pumps are connected to the outlet main pipe at the same time. When any two main feed water pumps are in operation, the remaining main feed water pump is on standby, thereby improving the water supply reliability of the main feed water system and reducing unplanned shutdowns.

[0020] The present invention arranges a connecting pipeline between the outlet pipelines of the first high-pressure heater and the second high-pressure heater, so that the first high-pressure heater and the second high-pressure heater can be used as backup for each other. After one high-pressure heater is disconnected, the feed water temperature changes relatively smoothly, avoiding a sudden change in the feed water temperature of the corresponding steam generator after the disconnection of one high-pressure heater, thereby improving the safety of the unit operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 This is a schematic diagram of the main water supply system of a high-temperature gas-cooled reactor in the prior art;

[0023] Figure 2 This is a schematic flow chart of the main water supply system for a high-temperature gas-cooled reactor provided by the present invention. DETAILED DESCRIPTION

[0024] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0025] The following describes a main water supply system for improving the water supply reliability of a high temperature gas-cooled reactor steam generator according to an embodiment of the present invention with reference to the accompanying drawings.

[0026] The main water supply system for improving the water supply reliability of a high-temperature gas-cooled reactor steam generator of the present invention comprises a main water supply pump and a high-pressure heater.

[0027] The main feed water pumps include the first main feed water pump, the second main feed water pump and the third main feed water pump. The outlet ends of the first main feed water pump, the second main feed water pump and the third main feed water pump are connected to the main pipe at the same time. The first main feed water pump, the second main feed water pump and the third main feed water pump supply water to the two steam generators through the main pipe, and the feed water flow of the steam generator is adjusted by the main feed water flow regulating valve of the steam generator.

[0028] Specifically, the outlet ends of the first main feed water pump, the second main feed water pump, and the third main feed water pump are all connected to the main pipe, that is, the main feed water pump pumps the feed water into the main pipe, and then the feed water finally flows to the steam generator through the main pipe. The three main feed water pumps correspond to two steam generators through the main pipe, thereby providing water to the two steam generators. In the present invention, the main feed water flow of the steam generator is controlled by the main feed water flow regulating valve corresponding to each steam generator, and the speed adjustment of the main feed water pump is only used as an auxiliary adjustment method. The present invention changes the control method of the main feed water flow of the steam generator, and no longer relies on controlling the feed water flow entering each steam generator by adjusting the speed of the main feed water pump. Therefore, there is no need to set an isolation valve or a check valve between the standby main feed water pump and the outlet main pipe of the running main feed water pump.

[0029] In the present invention, when any two of the first, second, and third main feedwater pumps are in operation, the remaining main feedwater pump serves as a standby. Specifically, the first, second, and third main feedwater pumps are simultaneously connected to the main pipe and serve as parallel standby. When any two of the main feedwater pumps are in operation, the remaining main feedwater pump can provide a backup for any of the operating main feedwater pumps, thereby ensuring the water supply reliability of the main feedwater system and reducing unplanned reactor outages. This can be particularly useful in the design of subsequent multi-module high-temperature gas-cooled reactors, improving overall system redundancy, enhancing safety, and saving equipment investment.

[0030] The present invention makes improvements on the overall process of the main feed water system, and improves the original design of one main feed water pump corresponding to one steam generator to a design of three main feed water pumps corresponding to two steam generators through a main pipe. That is, in the present invention, two of the three main feed water pumps are used and one is a backup. After any operating main feed water pump trips, the backup main feed water pump automatically starts to supply water, which will not cause the steam generator to lose water and stop, thereby ensuring the reliability of water supply.

[0031] In some embodiments, a deaerator is provided upstream of the main feed water pump, and the deaerator is used to remove oxygen from the feed water.

[0032] The high-pressure heater is arranged between the main feed water pump and the steam generator for heating the feed water. The high-pressure heater includes a first high-pressure heater and a second high-pressure heater. The outlet pipelines of the first high-pressure heater and the second high-pressure heater are connected.

[0033] Specifically, the high-pressure heater is arranged downstream of the main feed water pump. The feed water is heated by the high-pressure heater and flows to the steam generator. The high-pressure heater includes a first high-pressure heater and a second high-pressure heater. The inlet ends of the first high-pressure heater and the second high-pressure heater are connected to the main pipe. The steam generator includes a first steam generator and a second steam generator. The first high-pressure heater and the second high-pressure heater provide water to the first steam generator and the second steam generator respectively. The outlet pipelines of the first high-pressure heater and the second high-pressure heater are connected by a connecting pipeline.

[0034] The present invention connects the outlet pipelines of the first high-pressure heater and the second high-pressure heater through a connecting pipeline so that the first high-pressure heater and the second high-pressure heater can serve as backup for each other.

[0035] Specifically, when the first high-pressure heater or the second high-pressure heater is operating normally, the first high-pressure heater and the second high-pressure heater respectively provide water to the first steam generator and the second steam generator, and the first valve provided on the connecting pipeline is closed; when the first high-pressure heater fails, the first valve is opened, and the second high-pressure heater provides water to the first steam generator and the second steam generator, thereby avoiding a sudden change in the feed water temperature of the first steam generator when the first high-pressure heater fails, thereby improving the safety of the unit operation; when the second high-pressure heater fails, the first valve is opened, and the first high-pressure heater provides water to the first steam generator and the second steam generator, thereby avoiding a sudden change in the feed water temperature of the second steam generator when the second high-pressure heater fails, thereby improving the safety of the unit operation.

[0036] In some embodiments, the main feedwater flow regulating valve includes a main regulating valve and a bypass regulating valve, which are arranged in parallel. Specifically, the main regulating valve is arranged on the main feedwater pipe, and the bypass regulating valve is arranged on the bypass feedwater pipe. The main regulating valve and the bypass regulating valve are used to control the feedwater flow of the steam generator.

[0037] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms may be directed to different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are mutually inconsistent.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A main water supply system for improving the water supply reliability of a high-temperature gas-cooled reactor steam generator, characterized in that: include: Main feed water pumps, the main feed water pumps comprising a first main feed water pump, a second main feed water pump, and a third main feed water pump, wherein the outlet ends of the first main feed water pump, the second main feed water pump, and the third main feed water pump are simultaneously connected to a main pipe, and the first main feed water pump, the second main feed water pump, and the third main feed water pump supply water to two steam generators through the main pipe, and the feed water flow of the steam generators is adjusted by the main feed water flow regulating valves of the steam generators; A high-pressure heater is provided between the main feedwater pump and the steam generator for heating feedwater. The high-pressure heater includes a first high-pressure heater and a second high-pressure heater. The outlet pipelines of the first high-pressure heater and the second high-pressure heater are connected. The outlet pipelines of the first high-pressure heater and the second high-pressure heater are connected by a connecting pipeline, and a first valve is provided on the connecting pipeline. The steam generator includes a first steam generator and a second steam generator. When the first high-pressure heater and the second high-pressure heater provide water to the first steam generator and the second steam generator respectively, the first valve is closed.

2. The system according to claim 1, wherein When any two of the first main water supply pump, the second main water supply pump and the third main water supply pump are in operation, the remaining main water supply pump is on standby.

3. The system according to claim 1, wherein: The first high-pressure heater and the second high-pressure heater serve as backup for each other. When the first high-pressure heater or the second high-pressure heater fails, the first valve is opened.

4. The system according to claim 1, wherein: Inlet ends of the first high-pressure heater and the second high-pressure heater are connected to the main pipe.

5. The system according to claim 1, wherein: The feed water flow rate of the steam generator is assisted in adjusting by adjusting the rotation speed of the main feed water pump.

6. The system according to claim 1, wherein: The main water supply flow regulating valve includes a main regulating valve and a bypass regulating valve, and the main regulating valve and the bypass regulating valve are arranged in parallel.

7. The system according to claim 1, wherein: A deaerator is provided upstream of the main feed water pump, and the deaerator is used to remove oxygen in the feed water.

Images